The initial moves which culminated in the planning of the Expedition were made
in the summer of 1965. Several members of the Oxford University Cave Club took
part in the British Speleological Expedition to the Cantabrian Mountains 1965
(Ref. 1). This venture was itself in part a result of several years' work in the
locality by the Club (Refs. 2, 3, 4.). While some of the 1965 party were
returning to England they chanced upon a promising caving area in the vicinity
of Castro Urdiales, a small port some 30 km west of Bilbao (Fig.1).

In the Long Vacation of 1966, six members of the Club spent five weeks in this
area and ascertained that it was indeed worthy of a detailed investigation,
though this was not possible at the time owing to the general lack of equipment
and personnel. Further reconnaissance work in several other areas reinforced
this view. On our return to Oxford in October 1966, we therefore began to plan a
larger and more comprehensive expedition. It was decided that merely to explore
the caves would not be the most rewarding or interesting approach, and that a
fuller programme was necessary. The Cave Club members were therefore
supplemented by a geologist and a zoologist. The botanist who was to complete
the trio was unfortunately unable to go due to illness.

The large size and the unspoilt beauty of the caves discovered in 1966 suggested
that the making of a colour film would be worthwhile. This was a completely new
venture for the Club, and it was only definitely arranged at the last minute,
when an experienced amateur cine photographer was persuaded to join the team.
The final Expedition, as detailed below, was thus able to undertake a wide-
ranging survey of the area, and individual reports appear below. The work on
which they are based took place in both 1966 and 1967.

Experience gained in previous years suggested that it was both cheaper and more
convenient to buy all food in Spain. As a result of this, and the specialised
nature of the equipment required, no use was made of the O.U.E.C. scheme for
obtaining supplies. The Cave Club and the members of the Expedition provided the
bulk of the requisites, and the main expenses were extra caving tackle and the
film. Members also provided the three vehicles (two Land-Rovers and a van). The
organisation was thus considerably simplified, but was in return complicated by
troubles with personnel: three prospective members dropped out a few days before
our departure.

Seven members in two vehicles left Oxford on July 11th, arriving at Castro
Urdiales on the 13th. The rest left on the 14th and arrived on the 16th, delayed
by the personnel problems just described.

It had originally been hoped that the survey of the Castro area would take a
relatively short time, and that the underground features in the Udias polje
could be explored in association with the S.E.S.S., a Spanish caving group. This
was not possible, however, as the absence of three cavers from the Expedition
meant that the work at Castro took longer than intended, the Udias system was
said to be far larger than expected (beginning with a 500 ft mine shaft), and
the S.E.S.S. provided only one person, instead of the expected team. In
consequence the Expedition concentrated on the Castro area, although two of the
party spent four days at Udias.

Reduced camp-site charges had been negotiated in 1966, and a permanent base was
established at Samano, some 3 km from Castro. The Land-Rovers proved invaluable
for reaching the caves with the large amounts of equipment necessary, and the
Expedition was planned to be able to support two underground parties at once.
Three major and several minor systems were explored and surveyed. The film was
eventually completed and the sound-track added in June 1968. Detailed geological
maps (Figs. 2, 3) and a comprehensive zoological collection were made.

The film unit set out to do something that had never been done before: to make a
colour film in caves that were largely unexplored. Furthermore, we were
determined that this film should be shot almost entirely underground, dispensing
with shots of surface preparations.

The budget available for this project was extremely small; fortunately St.
Catherine's College Film Society generously helped us with the major problem of
equipment, lending us a camera and tripod for the duration of the expedition,
and editing equipment on our return. We owe them a tremendous debt of gratitude.

We had to use 16 mm film, as this is the universal gauge for documentaries of
this sort, and this led to the choice of Anscochrome 200 as film stock. This
film can be forced in processing to 400 A.S.A., making it the fastest 16 mm
colour stock then available.

Lighting posed a big problem as we could not afford to hire professional battery
lights. After considering various alternatives, we decided to make up our own
battery system, to use 30 volt, 275 watt photoflood bulbs. These are overrun
bulbs, giving much more light than conventional bulbs but having a much shorter
life. Consequently we needed to take many spares and these, together with the
film stock, accounted for the bulk of the budget.

To run the lamps we used five ex-Government non-spill 6 volt accumulators,
connected in series to give the required 30 volts. A junction board was
constructed, with connections for the battery wires, sockets for the lamp
connections (domestic 15 amp plugs and sockets) and a switch giving a 'warm-up'
position with only four batteries connected, to prolong bulb life. One of the
Expedition members provided stands and reflectors. Our battery capacity was only
sufficient to run three lamps, and these gave only 45 minutes light per charge.

We found in practice that our lighting was barely sufficient. However, more
lights would have needed extra batteries, and the additional load would have
been too much for our small party to transport. Colour balance was also a
problem, as Anscochrome was only available as a daylight film and so gave a
reddish cast to film exposed without a filter. However, we decided that this
would be acceptable in most shots, since the predominant colours in the caves
are reddish, and since the carbide lamps normally used by cavers also give a
very warm light. When filming sequences needing more accurate colour rendering,
with sufficient light, a pale blue filter giving partial compensation was used.
Our limited lighting prevented the use of a stronger filter.

To charge the batteries, we used a small ex-Government petrol charging set. This
broke down part way through our stay in Spain, and we then made arrangements to
have the batteries charged by a garage in Castro Urdiales. This proved to be
very convenient and inexpensive.

The first week in Spain we spent reconnoitring and scripting, while the
equipment was checked and tested on the surface, and then taken underground. The
camera, tripod, lights, bulbs, cable and batteries all had to be transported,
and this was a fairly strenuous operation, even with the whole Expedition
helping. The batteries, although heavy and bulky, had convenient rubber carrying
handles, and their steel cases were sufficiently robust to withstand the rough
treatment they received. The camera and bulbs were packed in well padded
ammunition boxes, which also withstood the inevitable knocks very well.

Many of the passages and chambers in which we filmed were very large, and this
presented a problem, since it was often impossible to illuminate large areas
sufficiently. Much of the film therefore had to be confined to medium and close
shots, concentrating on individuals rather than groups, and single formations
rather than "cave-scapes". However, a technique of illuminating only selected
areas in the field of view of a long shot was sometimes used and proved quite
effective.

We were worried about deterioration of the exposed film, and sent each reel off
to England for processing as soon as it was finished. These were not sent back
to us in Spain, so we could not see any rushes until all shooting was finished.
Inevitably, there were many shots we would have liked to retake, and this posed
problems which had to be solved in editing.

A print was made of the edited film, and a magnetic sound track added,
containing a commentary and effects (recorded in English caves) to complete the
film. This final version, entitled "First Light", runs for some twenty minutes
and demonstrates some of the problems and the possibilities of cave exploration.

Castro Urdiales is situated on the northern flank of the Cantabrian mountains.
This range dates from the Hercynian orogeny, but was re-elevated during the
Tertiary. All the rocks observed were of Cretaceous age, and owed their tectonic
disturbance to the Tertiary earth movements at the time of the Alpine orogeny.

The oldest rocks are sands and shales of Lower Cretaceous age, and are described
below as Wealden. These are overlain by a series of Upper Cretaceous (Urgonian)
limestones. In most places the basal limestone unit is a fine-grained grey
limestone containing abundant recrystallised casts of unbroken bivalves. This
was termed the 'bivalve unit' and is represented on Fig. 2 as 'argillaceous
limestone'. The bivalve unit is conformable on the Wealden, locally passing
through a distinguishable transition unit containing many orbitolinid fossils.
Overlying the bivalve unit is a series of reef limestones. These are typically
variable, with few signs of bedding, and consist of fragmented fossil remains
occurring with whole shells possibly in position of growth. Associated with the
reef limestones are extensive outcrops of clean, well-bedded bioclastic
limestones, presumably formed by accumulation of reef detritus.

The inferred palaeogeography is of a shallow sea fringing a land mass to the
south, with brackish or muddy water during Wealden times clearing during the
Upper Cretaceous. As the water cleared, reef formation began. The three main
reef masses (one extending eastwards from Monte Alegre and two connected masses
in the Punta Peña area, Fig. 2) were separated by channels with calcareous
shales and bioclastic limestones. The reefs were fringed by slopes of detrital
bedded limestone.

The limestones outcrop in two distinct areas, one to the north of Monte Cerredo;
the other south of Monte Alegre. The former area extends to the west to include
Candina and the Liendo polje. Dips on the northern flank of Cerredo average 300
to the north. The area south of Monte Alegre is smaller, but contains most of
the large cave systems, in addition to being structurally more complex. This
southern area, called the Punta Peña area, was therefore mapped in greater
detail (Fig. 2).

Structurally the Punta Peña area is a graben, set down by several hundred feet
within the surrounding Wealden by the Brazomar Fault, the Penilla Fault, the
Monte Alegre Fault and the Punta Peña Fault. Dips in the graben and around the
bounding faults were plotted stereographically, and it became clear that the
general dip of the rocks within the graben is to the south, although minor
flexures cause local deviations. The Brazomar Fault appears to be the axis of an
anticline separating the northerly dipping Cerredo area from the southerly
dipping Punta Peña area. Faulting is more important than folding in the Castro
Urdiales area, possibly because the Palaeozoic basement is not far below, the
faults at the surface being the expression of re-activated Hercynian faults at
shallow depths.

With the exception of the Iseca Nueva system near the Liendo polje, all the
major caves are in the reef limestones. This suggests that karst processes may
proceed more readily in the reef limestone than the bedded limestones, but only
the southern slopes of Cerredo (and hence the reef limestones of the Punta Peña
area) receive run-off from the insoluble Wealden outcrop. The bedded limestones
on the northern flank of Cerredo receive little or no run-off.

Studies carried out in the Cueva de Sangazo (Fig. 8) revealed the underground
continuation of the Monte Alegre Fault, near Carfax and also in the second Great
Chamber. The major north-south turn at the dry oxbow was shown to be related to
the zone of strike-slip movement mapped as the Dry Oxbow Fault. Although a
single well-defined fault was never seen underground, the considerable offset
had brought in the less soluble shaly beds and forced the stream to make a
detour at this point.

Stalactite development was most prolific in well-jointed limestones, and groups
of stalactites were frequently seen to be aligned along joints. The Cueva de
Iseca Nueva, the only large cave seen in the bedded limestones, boasted the most
abundant stalactite development. Most of its formations were dead, however,
suggesting that the strong outward draught in the cave was relatively dry, and
that a higher entrance may exist not far from the unclimbed terminal aven.

(This is a condensed version, prepared by A. G. Brooks, of the geological
report. The full report is shortly to be published in the Proceedings of the
Oxford University Cave Club, No. 5.)

Although most of the caves found on the 1967 expedition were known to the local
populace, very few of them had even been entered, let alone systematically
explored and surveyed. The few organised caving groups in Spain are unable to
cope with the vast potential of the country, and the district of Castro Urdiales
had hardly been touched until the Oxford caving expeditions of 1966 and 1967.

A rudimentary attempt had been made by an unknown group to survey la Cueva de
Iseca Nueva, apparent by the use of cigarette packets to mark survey stations,
and the upper levels of the Cueva de las Peines had been explored and surveyed
by the Club Carbonero, a Spanish rambling group. Most of the main stream cave of
Peines was explored and surveyed by the Oxford expedition of 1966; the
expedition of 1967 completed the exploration, but had no time for further
surveying.

Detailed surveys were made in 1967 of three caves: la Cueva de Sangazo, la Cueva
de la Penilla and la Cueva de Iseca Nueva. La Cueva de la Virgen, Udias, was
surveyed with SESS, (Sección de Espeleologia Sautuola de Santander).

Where necessary and practicable the surveying was carried out to Cave Research
Group Grade IV (angles measured to one degree by prismatic compass, elevations
to ten minutes by abney level, and distances to one foot), which was ample for
our purposes. Side passages and upper series passages were surveyed to Grade
III. The full scale plans can be seen in the O.U.C.C. committee room at 4 Keble
Road; much reduced versions, in which a lot of detail is inevitably lost, are
included in this report (Figs. 4-8, see Fig. 7 for Key).

The survey technique used was quite rudimentary, but proved to be fairly
accurate. One of the two men in the team carries a large Spanish carbide lamp,
and walks ahead until a suitable station is reached, paying out a tape to
measure the distance. The second surveyor takes bearings and elevations to the
carbide lamp, which is easy to sight in the gloom. He then sketches passage
detail, while the first man marks the new survey station, usually smoking a mark
with the lamp or building a cairn, and numbers it clearly. This makes any point
relocatable for survey branches or scientific work.

These surveys aided theories on the histories of the caves, and also gave some
insight into the regions geology and hydrology. As geological and hydrological
features govern the development of underground systems, these act as museums if
the correct conclusions are drawn from the evidence.

In the case of the Sangazo-Penilla system, surface surveying was also needed to
relate the two entrances. This was done by triangulation by theodolite from a
taped and levelled base line. Owing to the prevalence of gum trees, a plague to
the surveyor, it proved difficult to set out a base line longer than 600 feet.
The angles subtended were therefore rather small, and made the survey somewhat
inaccurate. The purpose of this survey was to find the relative positions of the
Sangazo and Penilla sumps, and hence to relate the two caves to each other. A
theodolite traverse was also made between the entrance of Peines cave and its
resurgence about 500m away, showing the entrance to be some 130 feet above the
downstream sump. This cast some doubt on the rough-and-ready levelling methods
used in the 1966 survey of the cave, which gave the entrance as 180 feet above
the streamway.

All the survey data was analysed on a digital computer, converting the polar
coordinates to cartesian coordinates for accurate plotting. This programme also
provides for error distribution in interacting survey loops or traverse
closures, which on test data has resulted in a useful reduction in survey error.
The details of the programme are too technical to describe here. Where there
were traverse closures, the closing errors were of the order of 0.5%, a very
reasonable figure considering the conditions encountered when surveying.

Cave surveying is a cold, wet, hungry and time-consuming occupation. Trips
underground can last over twelve hours non-stop. However, the fascination of
plotting out the data and finding out where the passage really does go is
sufficient reward and the results are often surprising.

The twin caves of Sangazo and Penilla appear to be entirely separate to an
observer looking only at their entrances. However, the distance between their
ends is only some hundreds of feet, and the water which enters Penilla is
certainly that which flows through Sangazo cave. It was, in fact, a great
disappointment to the expedition not to discover a passable passage joining the
two caves, especially as parts of them showed such initial promise.

On entering the lower entrance to Sangazo (Fig. 8) one quickly comes to a dam,
constructed by the Castro Urdiales water works department. One climbs this, and
wades through the lake beyond, chest-deep in water. After this baptism, one
continues along a large and pleasant streamway, some twenty feet wide and thirty
feet high. Here formations are fairly infrequent, apart from large stal flows
cascading down from the old upper series passages. About halfway along this main
passage, a dry oxbow allows a short detour around an unpleasantly deep pool.
This detour is beautifully decorated with some fine rimstone pools, and a
crystal-white calcite floor. One especially fine stalagmite was immediately
called Mount Vesuvius.

After the oxbow the whole nature of the passage changes. Whereas previously it
was substantially straight and of uniform section, it now continues in a series
of right-angle bends as it follows the joint pattern of the limestone massif. In
places the roof descends and one is forced on to hands and knees. Some two
thousand feet beyond the oxbow the stream passes through a large boulder choke
and the passage continues into the sump complex - a maze of passages, pools and
interesting little sumps. A tight and unpleasant passage leads on to the main
sump which, due to its great size makes a fine end to the streamway.

If one could dive through this sump one would emerge in the Penilla sump, which
is also on a grand scale (Fig. 4). One has to swim along a hundred yards of
flooded passage to reach it - a chilly occupation. From here a pleasant passage
zig-zags its way towards the surface, opening out on its way into a most
impressive chamber, which has at one point a natural rock arch soaring across
it. From here a short scramble among the boulders leads one to the surface,
emerging through a vast natural archway. The main stream in fact sinks in the
boulders of the Penilla main chamber, and re-emerges in the Sangazo boulder
choke; only a part of the water now flows through the sumps connecting the
caves.

In contrast to the (geologically speaking) young streamway, the upper series of
Sangazo are old, silent and decaying, but nevertheless they are still
interesting. The great chambers at first impress one with their vastness, the
caver with his meagre lights being lost in the gloom, at times totally unable to
see either the roof above him or the walls around. The silence and the clay
covered boulders begin to weigh on the imagination, and it is pleasant, by
contrast, to enter a smaller side chamber, named Fairyland, well blessed with
magnificent brown and white stal flows and dry calcite pools.

The upper entrance series is an intimate jungle of passages. In all, it is
possible to distinguish three separate ways, criss-crossing with each other and
the main streamway. In many places one finds the most splendidly decorated
grottoes. All in all, it forms a gay little second entrance to the cave.

The cave's attraction was not solely confined to the physical layout of the
passages, because some of the discoveries made in them were quite surprising. In
parts of the entrance series large deposits of ice-age animal bones were found,
cemented together with calcite. We had no equipment for excavating them, so they
remain undisturbed for some future paleontologist. This prompted a search for
cave paintings, remembering that they were found in nearby Altamira, the famous
cave, but we drew a blank. Perhaps we shall have better luck in the future.

Location: Take the road from Castro Urdiales up the hill towards Goriezo and
then turn left down a narrow road opposite the turning to Montealegre. Beyond
some new houses it is possible to park and a track leads across fields to the
resurgence. The upper entrances are now barred and locked, but it is lower
entrance is still open. Presumably the deep water behind the dam is presumed to
deter casual explorers (only 1m deep!).

The locals refer to this cave as Cueva de la Lastrilla. Lastrilla is the name
of the locality of the buildings nearby. Sangazo is the name of a similar, but
more distant locality. The correct name for Penilla cave is Cueva de la
Cubilla.

The mountain of La Peña (470 m) lies due south of Castro Urdiales, about five
kilometres from the coast, and forms the south-west edge of the Samano syncline
(see P. Rat, 'Les Pays Cretaces Basco-Cantabriques', Dijon, 1959, p. 393). The
mountain is skirted on the north side by the road from Samano to Santullan which
provides the easiest access to it. Though not very high, the mountain is
extremely spectacular and forms a conspicuous landmark rising abruptly as a wall
of grey limestone from the lush green plain of Samano only a few metres above
sea level. The mountain has been left isolated as a long narrow ridge by the
more rapid erosion of the softer Wealden beds to the south-west. Streams flowing
northwards off these sandstones, such as the Arroyo de Tabernillas, sink into
the limestone on the south flank of the ridge, their combined waters re-emerging
at the single resurgence of La Suma.

This forms the setting for the discovery of the most beautiful cave explored by
the Expedition in the Castro Urdiales area, the Cueva de las Peines (Fig. 5).
This was first entered by the 1966 expedition, which partially explored the
cave, and completed a low grade survey. The exploration was completed in 1967.

The entrance is located in a eucalyptus plantation on the hillside about 0.5 km
west of the resurgence of La Suma. A small hole under a boulder gives access to
the upper cave, a complex of dry galleries and chambers descending quite steeply
to a deep canal. The upper cave was once well decorated but most of the
formations have now been spoilt by local visitors. One of the chambers has a
curtain of unique and sinister tree roots hanging quite forty feet from ceiling
to floor.

At the bottom of the upper cave, down a muddy slope and a short stalagmite
climb, a deep canal is reached. This was the limit of penetration by previous
explorers, as the canal is here some eight feet wide and eight to ten feet deep.
Downstream, is possible to swim for a long way until a boulder choke is reached;
this probably lies immediately beneath a collapse by the roadside only a short
distance from the resurgence of La Suma. In common with many resurgences in this
part of Spain, La Suma has been dammed for water supply. A short mined passage
near the point of debouchure of the water leads into a stream passage with a
concrete dam twelve feet high. This is probably responsible for the deep water
further up the cave as the passage gradient is extremely slight.

Upstream in the main cave, progress is made either by traversing along in the
roof of the passage or by swimming, each way sufficiently unpleasant to have
deterred previous inexperienced explorers. Hence from this point onwards the
cave was completely virgin. The water remains deep for several hundred feet
until a short tributary passage (Waterfall Passage) is reached after which it is
possible to wade. The water from this passage pours down a small waterfall on
the left. The passage was explored for about fifty feet to an impenetrable sump.
The main cave continues as several thousand feet of beautiful stream passage,
large, clean, and superbly decorated. The stream flows over clean rock with an
almost complete absence of alluvium, while the finely scalloped passage meanders
in smooth curves. There are many oxbows and roof climbs, all with exquisite
formations in active development. One high level oxbow has a fine series of
rimstone pools and was named The Shrine. The main passage ends with a short
phreatic section followed by an impenetrable and extremely unstable boulder
choke. A grotto up an inlet near the terminal choke contains some fine four foot
straws and pure white stalagmite flows. Here an interesting climb up a scree
slope of loose stones cemented with mud and rotten stalagmite leads to a large
dome-like chamber which contains a large group of twelve foot straw stalactites.
One of these was probably a full fifteen feet long and quite unique.

The possibilities for extending this cave are not good due to the instability of
the terminal choke, but the end of the cave is still far from the main sinks.
Nevertheless, although the cave is not particularly long we rate it a major
discovery on account of its incredible beauty, recorded in our film "First
Light".

WWW Editor's note: SESS returned to the region in the 70s and published a
substantial report (6) giving full recognition to the prior OUCC work.

The cave of Iseca Nueva has two entrances beside the track
leading to the village of Iseca Nueva. A stream emerges from one of these, and
is dammed to provide a water supply. The other, Cowsh Cave, is presumably a
flood resurgence; the entrance contains an unpleasant-looking pool from which
cattle drink.

We first found the cave on an exploratory trip around the area, some twelve km
west of Castro Urdiales. Several members of the expedition made a preliminary
reconnaissance in ordinary clothes. They entered over the low dam, rather than
wade through the most unpleasant mud in Cowsh Cave. When they reached the first
fork in the passage they took the easier route, because of their lack of kit,
and soon found their way blocked by a boulder choke. However, they reported on
their return that they could hear a waterfall up the other passage, beyond a
fairly easy crawl. A few days later a properly equipped party passed the crawl,
which proved very short. The waterfall was no more than a small step in the
stream bed, the noise from which had been amplified to an extraordinary extent
by the acoustics of the passage. This was thereafter called the Three-Inch
Waterfall.

The passage continued to be fairly spacious, with two further branches. There
were obvious signs of previous exploration, and many cigarette packets placed on
cairns or stalagmites which were presumably survey points. After the second
branch, the main passage changed into a long and wide crawl until the terminal
boulder chambers were reached. These were spacious, and were the limit of our
exploration of the cave. The main stream passed through a sump. Nearby was a
boulder fall, from which a draught could be felt. A high-level passage led to an
aven, which we were unable to climb. This was most disappointing as the aven
seemed to offer excellent prospects of completing a through trip. Many
indications, including the dryness of the draught, the surface topography, the
presence of many germinating seedlings and a distinct smell of fresh air at the
end of the cave, lead us to think that the point we reached is not far from
daylight.

The whole of the cave is very well decorated. Large stalactites hang from the
roof in beautiful and dangerous profusion. The main passage is in the process of
being abandoned by the stream. When we explored the cave during a drought - most
of the stream flowed in a small channel which sometimes crossed the main
passage, and could sometimes be heard nearby, but at other times was completely
separate. It was obvious, however, that in normal weather most of the water
would still pass along the main passage.

During the latter weeks in Spain, two of us left the main party to visit the
area of Udias, 70 km west of Castro Urdiales, between Santander and San Vicente
de la Barquera. We arrived with 'Ringo' (R. Rincon Vila), the only member of the
Santander caving club available, and set up camp below a small cave which Ringo
maintained was covered in cave paintings; we were not convinced.

Our objective was to descend the cave of Udias, which is entered from a mine
shaft, and the next morning we set off in search of the "hombre del las minas",
the bearer of all information. Two days later we still had not found him.
Meanwhile we searched on our own, finding nothing but holes full of village
rubbish. One hole more promising than most, the Cueva de la Virgen
Survey was found to be a through cave. Unfortunately it was just
downstream from La Virgen village, and the resulting smell proved too much for
one of the party. Thus, when we found we had got through, only two of us
returned for surveying.

The stream winds along the bottom leaving many ledges above, and traversing
along these was a distinct advantage. The survey was more beautiful than
accurate, partly due to the confusion of passage lengths measured in feet, and
widths and heights estimated by Ringo in metres. Compass (brujula) readings were
read out by me in Spanish. Ringo's English was hardly fluent, but was perfect
compared with my Spanish!

We never found the 'man of the mines' and his substitutes proved woefully
inadequate. The mine that we were assured led to the Udias cave was very
interesting, but most definitely not a cave.

Our thanks are due to the Gilchrist Educational Trust and the Spalding Trust
which gave us financial support, to St. Catherine's College Film Society which
provided much of the equipment needed for the film, and to the Samano camp-site
proprietor, who charged the expedition reduced rates. Thanks are also due to all
those who helped the expedition personally, especially the Speleological Society
of Santander, M.H.R. Soper, Esq., our home agent, and Mrs. Christiane Sanders,
who allowed the expedition to use her normally neat and tidy home as the
assembly point for personnel and equipment.